Control system



Feb. 5, 194s. H. L, NEWELL 2,394,399

' CONTROL SYSTEM Filed May 18, 1944 2 Sheets-Sheet 1 .1: -f f f s 595i: i ff//fsi' s sie s a: is. i i i; E E y 5 i; Q I: fy E: :E i: :E e E: l O 'x Ef' i Q 0 r :lv o n l Inventor:

Heber- L. Newell,

I Fab 5, 1946. H. L. NEwELL. i

CONTROL SYSTEM Filed lay 18, 1944 2 Sheets-Sheet 2 Inventov:

Hvebe- L. Newell,

, (11M/wl H ns' Aitor-neg ber 30 is periodically oscillated through a fixed path. This is accomplished by means of a suitable constant speed timing motor 36 of any suitable well-known construction, which motor drives a crank 31 which is mechanically interconnected with the support 35 by means of a link 36. The motor 36 is energized from a suitable electrical source of supply 39, and as it continuously operates it oscillates the contact member 30 through its ilxed path of motion.

Cooperating with the two oscillating contacts 32 and 33 respectively are contacts 40 and 4|. The contact 40 is mounted upon an electrically conducting strip 42 which in turn is secured to an electrically insulating block 43; this block is freely rotatable on the shaft 24. In a similar way the contact 4| is secured to an electrically conducting strip 44 which is secured to an insulating block 45 which also is freely rotatable on the shaft 24. The supports 35, 43 and 45 are separated by spacers 45a and 45h mounted upon the shaft 24.

As shown diagrammatically in Fig. 6, the contacts 32 and 40 control the energization of the heating element I8 and its lamp 20 so that when the contacts are closed both the heater and the lamp are energized, whereas when they are open both the heater and lamp are deenergized. In a similar way the contacts 33 and 4| control the energization and deenergization of the heating element i6 and its associated signal lamp 2|.

Controlling the coaction between the contacts 32 and 40 and the contacts 33 and 4| respectively are suitable control levers 46 and 41 which are mounted upon the vertical shaft 24 for free rotation with reference to it, and which are properly spaced by spacers 45e and 45d. As shown, the two levers 46 and 41 are provided with U- shaped end sections 46a and 41a which are `iournaled on the shaft 24. Interposed between the two arms of these U-shaped members are compression springs 46b and 41b which bias the upper arm of the upper U against the under surface of the member 28 and the lower arm of the lower U against the top surface of the bottom wall 21. This is for the purpose of holding the levers 46 and 41 in their adjusted positions by the frictional forces between the cooperating surfaces. Interposed between the lever 46 and support 43 is a tension spring 48, while a similar spring 49 is interposed between the support 45 and the lever 41. These two tension springs bias the contact 40 toward the contact 32 and the contact 4| toward the contact 33. In other words, as the contact member 30 oscillates to oscillate its contacts 32 and 33, the contacts 4i! and 4| tend to follow these two oscillating contacts respectively. However, the levers 46 and l41 control the motions of the contacts 40 and 4| so that only one at a, time can energize its associated contact 40 or 4| whereiby only one of the heaters i8 or i9 can be energized at a time. This is accomplished by means of stops 50 and provided on the levers 46 and 41 respectively and which are arranged to engage adjustable abutments 52 and 53 mounted on the supports 43 and 45 respectively. The adjustments of the levers 46 and 41 and hence of their stops 50 and 5| control the extent of movement of their associated contacts 40 and 4| in following the movable contacts 32 and 33.

The position of the lever 46 is adjusted by means of a control lever 54 pivotally mounted on the bottom wall 21 of the casing, which lever is connected with the lever 46 by means of a link 55. In a similar way the position of the lever 41 is controlled by a lever 56 which is connected to the lever 41 by a link 51. The two levers 54 and 56 extend through slots 53 and 53 respectively provided for them in the front wall of the casing i3, and on the exterior of the casing they are provided with knobs 60 and 6| whereby the levers may be conveniently operated.

It will be observed in view of the foregoing that when either of the levers 54, 56 is adjusted in its slot it will adjust the position of the associated lever 46, 41, and hence will adjust the position of the corresponding stop 53, 5|. If the stop 50 'be in its adjusted position shown in Fig. 6, then the contact 40 is in engagement with and is permitted to follow the movement of the contact 32 throughout its complete path of motion, whereby the heating element I6 is continuously energized throughout the complete stroke of the contact 32; and therefore for 100 per cent of the measured time interval. On the other hand, ii the stop 5| is in its position shown in Fig. 6 it holds the contact 4| in such a position that it will not engage the contact 33 at any time during the complete oscillatory motion of the latter contact, whereby the heating element i9 remains completely deenergized throughout the measured time interval. Now if the stop 56 be moved counter-clockwise (Fig. 6) toward the associated abutment 52, then at some point in the oscillation of the contact 32 the motion of the contact 40 will be stopped and hence the element I6 deenergized. The proportion of time that the element il is energized to the time that it is deenergized, of course will depend upon the position of the stop 50. Also, if the lever 56 be adjusted to move the stop 5| clockwise (Fig. 6), then the contact 4I will move toward the contact 33 and eventually will engage it for some portion of its stroke so as to energize the heater I9 throughout this portion; throughout the remaining portion of the stroke of the contact 33 the contact 4| will be out of engagement therewith and the element I9 will be deenergized throughout this portion. In this way, the two heating elements I6 and I3 are alternately energized, and by adjusting the positions of the knobs 60 and 6|, the percentages of time that they are energized are varied. When the knobs 60 and 6| are in their inner positions with reference to their slots 56 and 53, as shown in Fig. 2 in dotted lines in the case of the knob 60, and in solid lines in the case of the knob 6I, then both elements I8 and I9 are completely deenergized throughout the full stroke of the contact member 3|. By moving the knobs 60 and 6| outwardly from these inner positions, the percentages of time that the elements are energized are increased.

However, the two control levers 54 and 56 are mechanically interlocked so that when one of the heaters i6, I3 is energized for a portion of the period of movement of the oscillating contact member 3|, the other can be energized only for the complementary portion remaining of the period, but this other heater element can be energized for any portion of this remaining complementary portion from zero per cent to per cent thereof.

In the specific example illustrated, this interlock comprises a rigid rod 62 which is mounted in bearing members 63 and 64 rotatably mounted upon the two lever arms 54 and 56, respectively; the rod is freely slidable through the members 63 and 64. On one end of the rod 62 at the left of the bearing member 63, as viewed in Fig.J

3. is a cotter pin 55. while at the other end of the rod outside of the bearing member'64 are suitable adjustable nuts 66, the cotter pin and the nuts acting as stops cooperable with the bearing members 63 and 54.

It will be observed in view'of the foregoing interlock arrangement that both of the levers 54 and 56 can be freely moved to their inner or ofi positions at the same time, but that only one of these levers at a'time can be moved to its extreme outer or high heat position. (In Fig. 2 the solid line position of the lever 54 is its high heat position, while the solid line position of lever 56 is its oif position.) If the lever 54 be moved toward its low heat positionto some intermediate position, then it is obvious that the lever 56 is freed to be moved toward the right toward its high heat position to some intermediate position. Furthermore, it will be observed that if the lever 54 is in the aforementioned intermediate position, the lever 55 can be moved from its o position to any position between the "oiT lposition and itsy aforesaid intermediate position, which intermediate position is always complementary to the position of the lever 54 in the sense of the extent of movement that it is permitted to go. In this way, while either heater I8 or i9 can be energized from zero per cent to 100 per cent of the time of one complete oscillation of the member 30. the other heater canl be energized only for the complementary remaining portion of this interval of time. However, this otherl heater can be energized through the complete range from zero per cent to 100 per cent of this complementary portion of time.

While I have shown a particular embodiment oi my invention, it will be understood of course that I do not wish to be limited thereto since many modifications may be made. and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of ti'. United States is:

1. A heating system comprising a pair of heatsaid control elements from its oi position is limited to a maximum heat position wherein its associated heating element is energized only for the complementary portion remaining of said time interval, said iiexible interlocking means, however, providing for unrestricted movement of said other heat control element to any intermediate heat position between said off and maximum heat positions to energize its associated heating element for any degree of enengization from zero per cent to 100 per cent of said complementary portion.

2. A heating system comprising a pair of heating elements, a time element switching. mechanism for controlling the energization of said heating elements provided with afirst pair of control contacts reciprocating back and forth in unison in a predetermined timed interval, a second pair of contacts cooperating with said nrst pair respectively so as to control the energiz'a.- tion of said heating elements respectively, means biasing said second pair toward engagement with said nrst pair so that they can move with said first pair in engagement therewith, adjustable stops for limiting the movement of said second pair of contacts in order to determine the proportion of said time interval said heating elements are energized respectively, interlocking means between said stops for controlling their relative adjustments so that one heating element can be energized for only the complementary portion remaining of saidtime interval that .the other is energized, said interlocking means however providing for relative adjustment of the stops so that said one heating element can be energized from zero per cent to 100 per cent oi' said complementary portion. d

3. A heating system comprising a pair of heating elements, a switch member mounted for osing elements, time element switching means for measuring a predetermined time interval and constructed and arranged to be operated alternateiy to energize said heating elements, separate control elements for said heating elements for selectively controlling said switching means. each movable through a predetermined range of motion from an 03" position to a high heat position cillating motion having a pair of opposed contacts thereon, means for oscillating said member through a determined path, a second pair o! contacts for cooperatingA with said nrst pair of contacts respectively, the two sets of paired contacts controlling the energization oi'l said two heating elements respectively, means biasing said second pair toward the respective contacts oi' said ilrst.

pair so that they tend to oscillate with said first pair and when either set is in engagement the associated heating element is energized. a pair of stops operably rassociated with said second pair of contacts respectively to control the extent of movement that the second contacts are inengagement with their oscillating contacts respectively, and an interlock between said stops controlling' them so that only one of said sets of contacts can be closed at a time, and said one set can be closed from zero percent to per cent of vthe motion of said oscillating switch member, while the other set can be closed from lzero per cent to 100 per cent `of the complemental-y portion of said motion remaining.

HIBERLNEWELL. 

